1. Field of the Invention
The invention relates to aqueous compositions, such as beverages, containing plant sterols for human and veterinary use and processes for their manufacture. Typical beverages include fruit and vegetable juices. Other typical beverages include sports beverages, drinks, or beverages employed to restore electrolytes lost due to illness. Further typical beverages include carbonated beverages including soft drinks and so-called “botanical flavor” drinks such as cola and other natural and artificial flavor drinks.
2. Related Art
Researchers have investigated methods of preventing atherosclerosis, one of the underlying causes of cardiovascular disease, and have evidence that cholesterol plays a role in this disease by contributing to the formation of atherosclerotic plaques in blood vessels, causing interference with blood circulation to the heart muscles, kidneys, brain, and limbs. Some data show that a 1% reduction in a person's total serum cholesterol yields a 2% reduction in risk of coronary artery disease and a 10% decrease could prevent about 100,000 deaths in the United States annually. As early as 1953, the scientific literature reported that plant sterols have some effect in reducing atherosclerotic events in mammals, reduction in blood serum cholesterol in man, and the reduction of serum cholesterol in young men with atherosclerotic heart disease. (Pollak, Circulation 7, 696-701; 702-706 (1953); Farquhar et al., Circulation, 14, 77-82 (1956)). Other scientific literature establishes that plant sterols and stanols do, in fact, lower the level of serum cholesterol in humans; however, because of poor solubility in water, it was difficult to prepare products suitable for human and veterinary consumption that contained these plant sterols or stanols.
For the most part, plant sterols or stanols were employed in margarines and other so-called spreads or similar food products because of their hydrophobic properties. U.S. Pat. Nos. 3,881,005 and 4,195,084, both assigned to Eli Lilly, describe grinding or milling plant sterols in order to enhance their solubility. Eli Lilly at one time marketed a sterol preparation from tall oil and later from soybean oil under the trademark Cytellin that lowered serum cholesterol by about 9%. Kuccodkar et al., Atherosclerosis, 23: 239-248 (1976). The product, however, never received widespread consumer acceptance.
Fruit juice-containing products, i.e., aqueous-based beverages and preparations containing fruit juice (as well as concentrates for preparing such beverages and products), are used in the art, and have achieved a relatively high degree of commercial acceptance. The incorporation of hydrophobic ingredients into these products presents a difficulty well known in the art since hydrophobic ingredients have a different density than water and as a result, at the time of purchase and consumption of the product, a hydrophobic component may separate and float to the surface or sink to the bottom. For example, the hydrophobic component that floats to the surface produces undesirable “ringing,” which is found in beverages, such as juices containing a hydrophobic ingredient with a density less than water, and results in a product that is non-uniform throughout the container.
Fruit juice-containing products packaged in transparent or translucent (e.g., glass or plastic) containers must avoid this separation since aesthetically undesirable visible separation of the product impacts on consumer acceptance. Agitation of the fruit juice-containing product in its container prior to use provides a temporary dispersion of the hydrophobic ingredient, however, this only amounts to a short term solution, as the hydrophobic ingredient can separate again following agitation. Hydrophobic, fat-soluble or oleophilic ingredients, including vitamins, oils, extracts, flavors, and sterols, when added to fruit juice-containing products require special treatment to ensure incorporation either by suspension or dispersion into the fruit juice-containing product so that they will not separate.
Prior art attempts to overcome these difficulties typically make use of several methods including homogenization, encapsulation, and/or the addition of stabilizers, gums, emulsifiers, and the like; however, these methods increase the cost of the product, and in some instances are illegal in certain standardized products such as, a citrus juice, e.g., orange juice. The consumer may also find some of these products undesirable from a labeling, texture, and viscosity standpoint. Stabilizers and gums often add viscosity, i.e., thickness to a fruit juice-containing product, thereby detracting from its organoleptic impression. Additionally, dispersing plant sterols in juices or drinks causes the beverage to have a powdery texture, which also impacts negatively on consumer acceptance.
Because of consumer recognition and acceptance, some juice beverages should maintain a turbid appearance and should not produce a ring at the surface of the juice when in the container or a glass, making it necessary to provide a fruit juice and/or fruit juice concentrate containing hydrophobic materials in a stable dispersion. Consumer recognition and acceptance of turbidity in some fruit juice products such as citrus juices, e.g., orange juice and other beverage products, requires stability of the product for this reason, both during refrigeration or the shelf life of the product, as well as at the point of consumption.
Tiainen et al., U.S. Pat. No. 6,129,944, describes a method for producing a product containing a plant sterol by forming a homogeneous suspension of a microcrystalline plant sterol and a sweetening agent in an aqueous solution.
Vulfson et al., WO 00/41491, discloses hydrophobic compounds such as plant sterols and lycopenes as supplements to food products and beverages such as oleomargarine products, drinks, soups, sauces, dips, salad dressings, mayonnaise, confectionery products, breads, cakes, biscuits, breakfast cereals, and yogurt type products. Vulson et al., in combining the plant sterol or lycopene with the food product, theorizes that the food product, which has both hydroxyl and carboxyl groups, interacts with the surface of the sterol or lycopene.
The reference goes on to describe producing a fine suspension of plant sterols in water in the absence of surfactants and without grinding the plant sterol with sugars, as disclosed U.S. Pat. Nos. 3,085,939; 4,195,084; 3,881,005; and GB 934,686. Vulfson et al. by contrast, forms a suspension or slurry of plant sterols in water at from about 10% to about 30% (by weight) of sterol by extensive homogenization using conventional methods and a small volume of a concentrated aqueous solution of the food product, which the inventors describe as a “coating material.”
Haarasilta et al., WO 98/58554, describes a premix used in the food industry containing a pulverized plant sterol and a conventional foodstuff ingredient such as fruit, vegetable, or berry type of material, particularly in a powder form and methods for preparing the premix. Grinding the plant sterol and the foodstuff such as berries, fruits, or vegetables according to methods and devices disclosed in Finnish patent applications FI 963 904 and FI 932 853 and with a grinder operating on the so-called impact milling principle, such as an Atrex mill manufactured by Megatrex Oy, produce this result. The inventors note that when applying the process of the invention to cereal in combination with a plant sterol, the temperature of the cereal grains rises due to the effect of mechanical energy on the grains, thereby providing heat treatment of the grains in conjunction with grinding.
Zawistowski, WO 00/45648, describes a method of preparing microparticles of plant sterols and plant stanols or mixtures of both by dispersing and suspending the plant sterols and plant stanols in a semi-fluid, fluid, or viscous vehicle and exposing the vehicle so formed to impact forces. The method involves dispersing or otherwise suspending the plant sterol and/or plant stanol in a suitable semi-fluid, fluid, or viscous vehicle followed by applying impact forces to the vehicle to produce microparticles. Zawistowski develops these impact forces by creating high-shear either with an air-atomization nozzle, a pneumatic nozzle, a high-shear mixer, or colloid mill, but preferably a microfluidizer commercially available from Microfluidics Incorporation, Newton, Mass.
Zawistowski observed that the plant sterols and/or plant stanols prepared in this way have greater “solubility” not only in oil based delivery systems but also in other media and can be incorporated into beverages such as colas, juices or dietary supplement and/or milk replacement drinks.
Gottemoller, WO 01/37681 A1, also describes a process of combining a plant sterol and/or plant stanol with a water-soluble protein and optionally an emulsifier by grinding the plant sterols and plant stanols or prilling it to produce a powdered product before adding it to an aqueous material.
Tarr et al., WO 94/27451, describes a process for making a thickener from citrus fruit for beverages by preparing a slurry of water and citrus pulp having a solids content of from 0.15% to 10% by weight (anhydrous) followed by heating the slurry to a temperature from 70° C. to 180° C. (158° F. to 356° F.) for 2 to 240 minutes, and subjecting the slurry to high shear treatment at a shear rate of from 20,000 sec−1 to 100,000,000 sec−1 by homogenization at a pressure of from 1,000 psig to 15,000 psig and colloidal milling.
It would be an advantage to overcome at least one of the difficulties in the related art. At least one of these other advantages are realized according to the present invention, which provides a process for producing a substantially stable dispersion consisting essentially of a hydrophobic plant sterol and an aqueous material such as an aqueous beverage concentrate, and products made by this process, all of which substantially obviate one or more of the limitations or disadvantages of the processes and compositions of the related art without, for example, increasing viscosity, imparting off-flavors, or a powder taste, introducing undesirable ingredients, or producing an undesirable visual appearance.
The specification sets out additional features and advantages which may be realized by the invention, which in part, a skilled artisan will find apparent from the description and may learn by practice of the invention, and who will realize the objectives and other advantages of the invention obtained by the process and composition particularly pointed out in the written descriptions and claims hereof.